1. Technical Field of the Invention
The present invention relates to a method and apparatus for removably holding various medical devices such as endoscopes used, for example, during surgical operations in cranial nerve surgery.
2. Related Art
An apparatus for holding medical devices (medical-device holding apparatus) has been known, which has a polyarticular arm equipped with a holder that holds medical devices and joints equipped with brakes to selectively lock/unlock the turns of the arm. This medical-device supporting apparatus allows the holder to support, for example, an endoscope so that the endoscope is positioned to face a desired portion to be examined of a patient. In this attitude of the holder, the joints are locked to prevent a field of view of the endoscope from deviating outside the portion to be examined. Thus a surgeon is able to concentrate on the surgical operation, without being bothered by positional adjustment operations of the endoscope.
Meanwhile, as described in Japanese Patent Publication (unexamined) No. 2002-345831, the medical-device holding apparatus has a grasping member which is used to move the holder (i.e., the endoscope), wherein the grasping member is arranged close to the holder. That is, in order to lock and unlock the brakes in the joints, the grasping member is arranged to substantially be perpendicular to an insertion axis assigned to the endoscope and is equipped two operation switches secured thereon. Thus a surgeon grasps the grasping member and, at the same time, pushes those two operation switches by, usually, the first and middle fingers. This push operation allows the brakes to be activated, so that each joint is released from being locked. In other words, in the condition where both the two operation switches are not pressed at the same time (, or together), each joint will not be released from being fixed. It is therefore possible for a surgeon to worry about erroneous release operations of the brakes during a surgical operation, so that the surgeon can concentrate on the operation.
Further, in operating the medical-device holding apparatus, it is required that a surgeon's touch to the arm will not move the arm under the condition in which the brakes have been locked in the joints. To realize such a situation, a large amount of fixing force should be given to each brake. In contrast, with the arm made free (i.e., the locks are released), it should be constructed such that a medical device that has been held by the apparatus can be moved freely with a light amount of operator's force. In addition, with taking malfunctions and others of the joints, design is made such that the brakes sustain a certain specific level of braking force to prevent the arm from moving in such malfunction cases.